Divtxti.Dia ss. In Sehott's T(chnica Ou•ioga, iu 16ii I. is deserilted a /oririi mingtica, or aquatic armor, %Odell eonsisted of a leathern fire--, to protect the diver from the water. and it In Ilall•v a contrivance of his own of nearly the saint. kind; its object was to enable the diver to go out from the bell and walk about ; he was to be provided With a Waterproof dress, and a ,111:111 diving-hell, with glass front, as a over hi. which was to be supplied with air by means of a from the diving-bell. In I7Os of 1;reslau vented a diving-dress available for (Hillis up to 20 feet. The head and hotly of the diver were encased iu cylindrieal tinplate armor, and his legs in leather breeches. Fresh air was von t eyed to him and the vitiated air was removed by means of pipes. in Is:nt August Siebe de vised an open-helmet diving-dress, having a copper helmet and breastplate, with attached canvas jacket below which the air was allowed but to avoid the admission of water the war forced to keep it vertical position. Lt IS39 Siehe improved his dress, which now is a waterpia,of costunie with helmet of tinned cop per, having circular glasses in front, valves to admit and discharge air, and a signal-line to allow communication with those above water. The weight of the dress is about 275 pounds. In
ISSO 1"leuss invented a dress weighing only '20 pounds. This has a copper cylinder fastened to the back, carrying a supply of compressed oxy gen. The earlionie acid exhaled by the diver is absorbed by caustic soda in a receptacle fixed above the copper cylinder. while the nitrogen is breathed over and over again. In this dress the diver may remain several hours below the face. For lighting, arc and incandescent lights are used. as well as improved oil-lamps supplied with air by force-pumps. Slates and are used for purposes of coimminieation. Accord ing to Siebe the greatest depth to wide]] a man has ever descended is 204 feet ; equivalent to a pressure of pounds per square inch.
(In all ships of the United States Navy. except very small ones. there is a complete diver's out fit. Nearly all gunners' mates are now instructed in diving and all reeently appointed gunners and boatswains are thoromdily conversant with the work. as are also the carpenters. Divers are used for examining the bottom, or cleaning it, overhauling the -drainers of submerged pipes, scraping the propeller, examining ehains. ing for articles lost overboard. etc. Men who are qualified divers ate given SI.25 for oath hour actually spent in diving in addition to the or dinary pay of their rating.